Homeland Security Secretary Janet Napolitano announced Friday she's stepping down to take a job running the University of California education system.

She also said that serving in the Obama administration has been a "privilege."

"The opportunity to work with the dedicated men and women of the Department of Homeland Security, who serve on the front lines of our nation's efforts to protect our communities and families from harm, has been the highlight of my professional career," Napolitano said.

Napolitano led the Department of Homeland Security throughout President Obama's first term. She is notorious for a memo in which she warned the government to be on the lookout for "right wing extremism."

Napolitano speculated that some military veterans and other conservatives, like pro-lifers, could be turning into dangerous radicals.

She later launched a partnership with Walmart and the DHS, encouraging shoppers to report any suspicious activity to the government.. Critics say that's one example of how she expanded intrusive levels of public and government surveillance.